Table 5. Sand Volume Requirements for Beaches of Inner New York Bight* 



Area 



Initial Fill 



Nourishment 







Annual 



50-Year 





X 10 6 



X 10 3 



X 10 6 



Rockaway 



4.20 



350.0 



17.5 



Coney Island 



4.50 



70.0 



3.5 



Sandy Hook to Monmouth 



6.84 



178.0 



8.9 



Staten Island 



2.60 



86.3 



4.3 



Raritan Bay-Sandy Hook Bay 



3.61 



47.9 



2.4 



Total 



21.75 



732.2 



36.6 



*Cubic Yards 



2. Suitability of Sand for Beach Nourishment. 



Sand useful as borrow material for beach restoration and protection projects should meet 

 certain important criteria. Factors to consider are: population mean -grain size and total size 

 distribution; mineralologic composition; and economics of recovery, placement and 

 distribution on the beach. Borrow material should be the same size or slightly coarser than 

 native material on the beach to be nourished. If borrow material is significantly smaller in 

 particle size than indigenous sand it will be unstable and out of equilibrium with the wave 

 and current regime. Consequently, it will be eroded and either carried offshore by 

 wave-induced currents or transported parallel to the beach as longshore drift. The net effect 

 in either case is accelerated retreat, and the fill, to readjust nearshore profiles would require 

 large total volumes. Borrow sand without the same size characteristics of the native beach 

 sand should be more poorly sorted (greater size variation), than native beach sand requiring 

 initial overfill. (Krumbien and James, 1965.) 



The borrow material should be composed of hard, chemically and physically resistant 

 minerals, such as quartz, which will not readily degrade in the high energy 

 nearshore-beach-dune environment. 



3. Potential Borrow Areas and Volumes. 



Results of this study indicate that large volumes of clean sand and gravel are widely 

 distributed over the Inner New York Bight shelf region. Based on examination of material in 

 the cores and by lateral extrapolation of stratigraphy on the geophysical profile records, 

 four areas are judged to contain potential material suitable for restoration and nourishment 

 of area beaches. (See Figure 22.) The individual areas are letter -designated and cover the 

 shelf region from the shoreface to about 80-foot depths. Cores in the borrow locations 

 shown in Figure 22 contain clean sand with sedimentary properties suitable as borrow 

 material. Numbers accompanying the core symbols are the minimum continuous sand 

 thicknesses in feet for the respective core. These thickness figures were then extrapolated to 

 peripheral parts of the borrow areas by distribution trends of sea floor sediment and by 



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